Sun Microsystems, Inc. was a company that sold computers, computer components, computer software, and information technology services. On January 27, 2010, Sun was acquired by Oracle Corporation.

In 1987, the company began using SPARC, a RISC processor architecture of its own design, in its computer systems, starting with the Sun-4 line. SPARC was initially a 32-bit architecture (SPARC V7) until the introduction of the SPARC V9 architecture in 1995, which added 64-bit extensions.

Since 2010, all further development of Sun machines based on SPARC architecture (including new Oracle SPARC T-series servers, SPARC T3 and T4 chips) is done as a part of Oracle Corporation hardware division.

The Java platform was developed at Sun in the early 1990s.

Sun sold its own storage systems to complement its system offerings; it has also made several storage-related acquisitions. On June 2, 2005, Sun announced it would purchase Storage Technology Corporation (StorageTek).